Fluid transfer pipes often crack, or break, completely due to various causes, such as the shifting of ground with respect to buried water pipes. In such cases, it is often not feasible to replace the pipe, since the particular piece of pipe having the breakage may be of a considerable length, and access to the entire length of the pipe may not be practical. For example, when an underground water pipe breaks, it may not be practical or feasible to dig up the entire length of pipe to replace it.
As a result, it is more desirable to mend the crack or the break in the pipe. A cross-section of a conventional apparatus for doing so is illustrated in FIG. 1, which shows breakage 11 resulting in pipe portions 1 and 2.
Pipes 1 and 2 are physically separated enough in order to slip nuts 16 and 15 onto pipes 1 and 2, respectively. Then, slip washers 14 and 13 are slipped onto pipes 1 and 2, respectively. Next, sleeve 12 is slipped over both pipes 1 and 2 so that it covers break 11. Nuts 16 and 15 and sleeve 12 are threaded so that they mate. Furthermore, slip washers 14 and 13 concentrically abut nuts 16 and 15, respectively, at concentric locations 17 and 18. Furthermore, slip washers 13 and 14 concentrically abut sleeve 12 at locations 19 and 10, respectively. Nuts 16 and 15 are tightened onto sleeve 12.
The inner diameters of washers 13 and 14 are designed to match the outer diameters of pipes 1 and 2 in order to provide a "water tight" coupling. Washers 14 and 13 may be comprised of a rubber or plastic-like material. The pipes and the other various parts shown in FIG. 1 may be comprised of polyvinylchloride ("PVC"), copper, plastic, rubber or any other pipe material often used for the transfer of fluids, such as gasses and liquids.
The desired result of compression coupling 3 (often referred to in the art as a "Dresser coupling") shown in FIG. 1 is to provide a "water tight" coupling between the two ends of the broken pipe. The fluid may enter into the chamber created by break 11, but will be unable to escape from coupling 3 due to the engagement between washers 14 and 13 and nuts 16 and 15, respectfully.
The problem with coupling 3 is that the fluid flow may be under a considerable amount of pressure. As illustrated in FIG. 1, that fluid pressure will flow in a particular direction from pipe 1 to pipe 2, which will tend to force a separation between pipe 1 and pipe 2 because of breakage 11. Often, this force is great enough to cause a slippage between pipe 1 and washer 14 and/or pipe 2 and washer 13, thus eventually widening break 11 so that one of the ends of the pipes escapes past washers 14 and/or 13 of coupling 3.
Thus, there is a need in the art for a technique for preventing slippage of such compression pipe couplings.